1. Field of the Invention
The present invention relates to a stack capacitor structure and a method of forming a stack capacitor structure. More specifically, the present invention relates to a stack capacitor structure having a connecting node for coupling two adjacent top plates, and a method of forming the stack capacitor structure.
2. Description of the Prior Art
As high density and high performance are required for a DRAM, cell capacitor technology needs to be developed to provide the required performance. Various types of capacitors have been proposed, such as a trench type and a stack type.
Generally, an increase in the cell capacitance can be achieved by both using high-k materials and increasing the surface area of the storage node. Even when high-k materials are used, much effort must be focused on enlarging the storage node surface area to maximize the cell capacitance. The surface area of a storage node is mostly increased by increasing the height since the design rule limits the horizontal dimension of the storage node.
However, if the capacitor is too high, the capacitor may collapse during the fabricating processes.